Brewhouse Efficiency Calculator

About this calculator

Brewhouse efficiency measures what percentage of a grain bill's theoretical maximum sugar (its "potential") actually ends up as fermentable extract in the fermenter, comparing the gravity and volume you actually collected against the gravity you'd get if every last point of sugar had been extracted from the grain and none were lost to the mash tun, boil kettle or trub. It is calculated from fermenter gravity and volume divided by the total potential extract implied by the grain weight and each malt's specific gravity potential.

Homebrewers and professional brewers alike track brewhouse efficiency to dial in recipe formulation — a lower efficiency means you need more grain to hit a target gravity, and a higher one means less — and to diagnose process problems like a stuck sparge, poor crush, or excessive kettle losses when a batch consistently comes in lower than expected.

This calculator takes your fermenter gravity, collected volume, total grain weight and grain potential, and returns your overall brewhouse efficiency percentage.